SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79ff750a4993c4a3aac3957fa7842b83f3c1a20bf651fdabb5e2021dd07ceb3b' 
  AND token = 'cuLgbyU0ZURfNq33d4WnOXIDhXOaN4Los0AI7JSqMoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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