SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a6bcbad1a6ded486028db3630053bc0ceb09516e02825c18b941b04ba41d04' 
  AND token = 'IrNFitbOfISqpOYJBqdBKv2AonlHU3/3ephR4l4ufrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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