SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47e070cd29006a99f53a2046f219ae0d574ee2502e26ab5a7e6d7ce6fe3e3c93' 
  AND token = 'n5R1yCLkKLF3ei46RZcs3/MRZ7myv/8WanLBxa+43pY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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