SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd049e70aa1083e1fc3c62d6ff822ae9913070e6752a17167166b5a3ac6fb8a0c' 
  AND token = 'MvIuyDZCy7+ZjWuOvxA+LMRqmwvDOhbGeD8MgdNo3Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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