SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9525b5e4c66e5391966a6dc67e090d607898abf8eff1c30f79012485955d3a8' 
  AND token = 'NbAMLlgraAVnISD+yVpYejhdFnc3sbKYnk5mkRqfm+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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