SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83da51a8f1050bea1668fab6381fd6e854b0717573fd32ce234692a8cfcc67a0' 
  AND token = 'foSwpP0/0oTFiabHSJtYUR4PKFn/8KaNTm2iUGpS20g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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