SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dcb53d7cd67de57832652d0e922438add41bdb368ac2f37b5805c9ef3f8a05d' 
  AND token = '6Q20YCPQ78MPxK+j7afJJTFD8NhhPMpo/7+UDjchZ84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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