SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb4608b985b401bfc2035b24f57bfa4adbe168098f5401238eaafe02ebb371d5' 
  AND token = '1Ccsd+c+oNcBM/nn0gv+Bt8jur4vbPzcQ7eLmhR+9Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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