SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f68d27a3dccec51ce9f2f943728421eb0f9746602f7917a9592a045117d6300a' 
  AND token = 'eet7yyXTIsiUTTiU/N1/uHMXdSmHpmBvGYcjtIr9YOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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