SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bafd70d58c936bf4c2cb446ec1a80b73b6708c0ca6e12718851d9516bfba02c' 
  AND token = 'MZiE/9CjN78hhRYgQ5KwiqfN4cq0aKBGkysoafxAUts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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