SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '85d242eea2c91eb6875ad5d66113a27b7653750c3a2eb3145ff9a56b10e5ccd8' 
  AND token = 'QCgP+jweJivV3B3W49N9YoGvOONLMnYOYCQChI9Cgbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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