SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afa7564b603d0233bcb742264610f4541bfad23c34148b287775098170014589' 
  AND token = 'VlIUXknzBDVBA0v1fWRd2L/sPOipegZJ+TQAhssAIEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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