SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4a161566d0da9b1418999c0d3bafff4d5975572086f94a8b1dd7bf4447b8f55' 
  AND token = '4IqbM1dpHPWvidCmJJCQENxM4YpIChqxiUkuYRd23xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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