SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb0778a1c664d23f51a1d32744d9972e38c4b06f1b51d885ed5c269f0d2c5159' 
  AND token = 'mDY2ZDCGx6rpiMb/ceOzBUKQ2XAQxIfR/0FIvjZRFhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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