SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6ed16110d7ca7cd509cbd98a521e601c5f361d3ecee0949351ecff72441cf96' 
  AND token = 'pSBqnH/aY0knUwyNEjkYeEdEdUXgkVv7Orc/rnghUws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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