SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f52cb98f20bd8d68ede80240841e8e838de5ca5cf2bfc5302f3fcf5105c4465' 
  AND token = 'EXdP+ZnFDqFK8NbKfrTnz/INc5V3jg17R/WnxkwZSsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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