SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96f3ba1562a8297e642f78509666d485c917bb9f9eaf2aca9c60ee9d1e62aae8' 
  AND token = 'mWKs4ON/FKW6lTmj36Dglz6T+LoQJc36ZPJAhOiMpFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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