SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2c097246683ce73e48e374774bfcafc65b009641cf6a4dc3254e8ab93ba2d0c3' 
  AND token = 'U6LSscBdo738RRdjPEzlcrbfFa7/E5rvX3O0IvgC8VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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