SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5a2eb50aef76e8264458671352b825e6d15cf911c40b8d4610e1aeb958f975f' 
  AND token = 'JzeLRIiKwtkEqmXQPviGwvjwMn/00Z1v7gIZjEQQOuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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