SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e14373c7df33fdf8e437d8a2b3478b1ed0e7e11dd765b85182e6ff2e9a83bea' 
  AND token = 'MelObFUoBbVStyo82KKhwwWfRKEa5RNkAN+XbPGrCWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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