SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cee4949f959f9792a857d595af0e212c1ecd20ff117547bc9f9c300fde576de' 
  AND token = 'nMWf2TsDGxeJvYhQ4hF+mkUYDLuZvO5Yk4NNIw5yJKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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