SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57e614887c2d994233e59dae1a33a388dd89cb49cfe1e03749d049de0fee908c' 
  AND token = 'pgJHJBgVJ0l+uXwtWfrkhZlIBoICtLpThumeg8y3OGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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