SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fb51f373fbd53c10d7193a578b0d27aabfaa61ae11f712e25220e7ea0918e737' 
  AND token = 'GdF27/+d6Nnrzcv9TKATT8ZcqX7jYNO5qAGAvpFmtQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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