SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc81ff743d33764f3884ae873063bf4059a51a6646285d621aa02b949560cf13' 
  AND token = 'yD4naw7ZLNsAfEnU1UVAEI2uTCsdbD5zqZXbF2sJqrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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