SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9221e9fcd81a213450bb8b8b4bd40aa6b5b33f3aec9248c56ee3e57033c7608' 
  AND token = 'EAjm/pOcIJN4sZlQhAPCcwWps+k4kvdw0/etOMCSO30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}