SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc79e2ea657fc8298bfba15d347bab514367ce6e13a20dc46ea120397d9afa71' 
  AND token = 'nWlsRrc9VWPETVKwAp+rvXpgVLclq8/BMZbjaDMgZcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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