SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a4f581692f2259b73d515b7c10eed641888d0b3f5a068f4d2d94aa3a069d12a' 
  AND token = 'YcwDE0mErR1KLledkLSdJkFMbFdIQquhiPFQX2HAFB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}