SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '624c58fac440cb6858872c577c309ff24eadcf25c54b521c93a8a7ecc8cd61a9' 
  AND token = 'rYlBss5dkv4K4BipcJEKCp+A63xNonCflS9NKSk1/qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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