SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7024aa9721cd72812ced1138064ff0871ab764236ba211940cdb1e161f0466' 
  AND token = 'k/+pFg+SltRBIYHMP2uuKeMcJ+rRrV7JkBfPHSyp4Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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