SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3367f0394795c6fa4042a86dfa7a84be8f100f9bb0e967d08346cd9eb2732595' 
  AND token = 'VBbnUppcocfyMaSxuxFHX/k00rFbPumk1uKdkrS2dDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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