SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14ffd136dd265e7254bda6d3969d5c65857859bfcfd88a48e55c4f9d00ca757b' 
  AND token = 'czXzj7Wdg0+016lAd67WNeNgv0SyFdT2PgGgu5burHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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