SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6964d56d5ebcc49b3b51183a80acf914bcee2ee77d6e01806277f8fe999a0bc7' 
  AND token = 'plKsq4Zp3uSEyGS+UFBdrm24dnPsvVioISP/WGHMr2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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