SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '531b745d0122c1d6a40d27ee86b1ae951a121b78acb3a69c135d91140db1f4bd' 
  AND token = 'JNhhM4FwHrg2zxq7yH/y/FhqS+cvvZ9VKLj6s+Nz3Mk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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