SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '746f6b48a0a77bfbdd42f401313aac6ab09925d39953b6ce499a20795531ccfd' 
  AND token = 'CgiUTK7PpZFdnoBlCrfEPcArrWoYHdNiMkdJv64zJC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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