SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce733e0a226d50dc54473645bd8b314dd4c4afdaef6f254e3d29ef340dfa424a' 
  AND token = 'L9x2KL4hvVgbRxJvwVU6/hapIL0f8F6WaWAMDvr0IjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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