SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63cec74b427861125bd334c978661324b209555efd53c6a4eaa4293d450e1b2f' 
  AND token = 'qa2qBPXsFWCJ0DcZrhdfTbMuBU5ll9uc76XFiAhGj6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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