SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71d6636992fc8515ca1c03e3dfd780fcc5442246d84d48cfb55fe09906bab58a' 
  AND token = 'tNv9yDmjLGtpnxJda6yAmsVE8nPZmzrVsCxAG7gbg5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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