SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a2ff3defca03a2fafad28c70c8ae74a42424505b790e6eef5193005e32c96aa' 
  AND token = 'cB+gmapjs7usIYmaeW/g/pCNkIdq2fRJ08K9h4kdcM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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