SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd51226958fb27037a3d49855ad8afc896cad91389c3f842b399bea91a0559e6e' 
  AND token = 'qwcILR+dR9ADhqXTeOAlaEz9p8SdoiEZyHitqKyf8bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00114

JSON explain

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