SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb45a96ba5a333117d5d1ab8e57ab087bd3db456ea82bcd3c4b55882123b992c' 
  AND token = '2U73Thz/0ADhEEwXAA7MKBURRB1fPXWxgTBAWDERqg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}