SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '160e340a96c5b09bbb278f20be4307a9a32b74a6e83f70f6e5d9bbf47e670ca3' 
  AND token = '5j+kwHiNN9t2q7+CxzLNOFmrHFdl8rv25HljcJwEeKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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