SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b539208913c77b711a81778a6fdc9305f3d59135cfc78cdbdb74107ae8a17478' 
  AND token = 'KbtXg5+BOPOERDbWheTuSZkiZGSEZHXLsihgM+wzYDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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