SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575e1fc2086f499abeca2b01f7df19a20f3da7833fe2a068a3b2ef1d01c385e4' 
  AND token = 'ZfNA3RPCmxArMLuPDDpBqivBn5XTFBaEm36QFLBxglo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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