SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dac0877de60c957a84e4c28f7d07b60250d98cdb92e10e470159d996eee645e' 
  AND token = 'L4YFKUK2woeUQZym1qrNT5+HsW2ph0Zfw6pXsWPBOPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}