SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76ab56d8151e786672b698a26206920c43ff1e824f471c59181e1aad8f648da5' 
  AND token = 'ZLOJR8HymgNr5CNJKqgUaopI6QaS9PXND/4JO7oHn6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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