SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f1386cc3c101f0dc1593df422f417b90ca1edd72b43ee997f58a78807f6be8f' 
  AND token = 'jJKkKK4bBo1lJKQG1BkoJzknxA9iKnuN01g1U2eFolw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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