SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdd52e97b1d3e9e68d714a45bcfa204d426ba7e7c495af92fbbc023d4b9e1e7' 
  AND token = 'py+ofu7HnTVdIQVICUsCnNmW8PKDZDPJvDvCPWuHDOI=' 
  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"
    }
  }
}