SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48d8d0d64205b1c351b1a03e913df367ee74f0e274c6cccea9de03d2af545f84' 
  AND token = 'n4BZhC31eT61YsZFNOVaOSYNDNJQG8zlfTI8xj0Sh4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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