SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9a3bff3a15d7e0fd3a50968cfaa091e0a5f963a863502dffab5148024fbe980' 
  AND token = 'F/lzm/9wUbVNgrsnFmyXW5TexELioURLYBRdrN84Pz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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