SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ba4387d99bc858334ac97ab10e7cd1a729fd16479931b985042fa457f3eace9' 
  AND token = 'rQMCqscjwbSK2xJgga2IcvcMnm8SOrqtW6HuET/lNO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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