SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1efa89d853658c223bf13ca2917e640e3fd02a5fb8ef0140edac0444bd9ee0d8' 
  AND token = 'd7GuJUlq+6uS0fl0b2A4hZamPVXdIypKlfWqpTPYkFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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