SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee37150d43ec1bd99b1ca7d992d6afe357bbf4566373d333415ef570b7bb424' 
  AND token = 'cj0JSMHuIAumFyTz3WcBI+BL2jQOkDCNtkAVjjKSw6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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