SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52bd6c8716caa5b9bacfe1ed03c4c5ba11eb19a97c2318e344c577316d1d26a6' 
  AND token = 'bUISpFmLw25USe+RsgLlA/TZbEvAkOcZZnYtoQB6sSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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