SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f5a9230b4cb2439c58d71f95f507302c697a0975d827aa2b82fa78162d2de46' 
  AND token = '9iv3+U0NudO2FKPYbeet8rl7vOq8fgTjYpKRZ8ZzHvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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