SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fc9cce13af78bad20abf9358f00cd474b65af74566569378f5c11fdec81dc5b' 
  AND token = 'jAotV2sIpaWdxbHmW7sDlLsVoHExw5rC9N1GmlDiP34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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