SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '656253494735d22874e283aae714e4b1e6b2184ccdefe54ae801a0e0628464bf' 
  AND token = 'Dcn/EyhRB53s+G+2Spc2COEGSrrLZP64pLpItoswmeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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