SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cac2af80263650c20767128d72cba8189bcb0173772cd715877097a1ab1d3453' 
  AND token = 'SAXLaPStbUlwwIYJjSNvxEFoZgDqxufvWSqpSoUazjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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