SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c76563b9ff68b8cc89ad66dbee5e9ced8ae335e1e52278cffe416208e01ea30' 
  AND token = 't9cP7ktvakoMstPdVPnLDiMJRqNgnr69g/tH2CSqsGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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