SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1642108af34eebf0903e821a18a0a15a5ec1bb664b303d27d31fef3f32260866' 
  AND token = 'MNf5M5QabyPcOaoVtFoAATncRo86xWBsI/69Gvfah+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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