SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0e059f1753c59685804d6acab09f018736d22675c5b9ee3ad92f933378656f8' 
  AND token = 'IPAarHAjb/SHqXvJ9snDoxFE7JbNqj6aaHOOUIwKdHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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