SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a0636e324c34f59880cf1e080c08147cc3a465c7820d50f1e2c608b75e5eb0' 
  AND token = 'q/aV9k7CG5fsJefXnTKguK05WSkikpHL/vFpQi8Wz6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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