SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc90ca07f0e6525d17ba72158f941382cd0d460931503833196d4bd2e1c96bac' 
  AND token = 'q4olWq1DzFZs41ERjuQecKv6iIo3EDBqG3YzY8+uBfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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