SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7efec4093c88797788ecb5ca0c5d3ffed6fd5488d29ae13e8a56f81d7377568' 
  AND token = 'Ldwe8A3qszOJXmxmjBKsn72BWHIiPVwPtqN/kEdZDHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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