SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0791a840a31498003fe6dea3ee618b60b1827ab2ca823abf8a9d88714dc86e00' 
  AND token = '74ZXxqmepEdgDnVH8CoPf8kALBfgY4umMAZlToLdrl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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