SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'acab672decca78ff6b4b1916cad76679278f95817d2fc881e86c7d4704748abf' 
  AND token = '0CEj/YAqpLUVe9t6t5CXkwiG8/89TGfSOWdOUTA6Bvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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