SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbd49408062ebde272b602931448b4b916cfc8841effcf1d9c7924bfdf32f0d' 
  AND token = 'XNeNwJCrAyp3gSGVCXU1YJ+j71iwxaWE20mSpRumaCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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