SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fc8f038982320f213b885cfb7c86cbc6b402f7a12185b0a51d35e916901585c' 
  AND token = 'gidaZIOIQjsTmuVrhO/fQWK4CeOvqOglozWDKkODyGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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