SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8799904fba852033aaf640e15374db2ef0fc75cb32303ae1107b1bf7f637f2bd' 
  AND token = 'rYgxoxZLbzxnRWxSC82MbSsr/VPq6yp1DDoJB04OD1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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