SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f1756df8560a9b36edcf9983f5fbbea38f38015574838960b8930570b95bfb0e' 
  AND token = 'G0YAMS5nCGrYIXqw+CUWWkaUWGGH0y0g7vHbSz6r/6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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