SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4215895adcfff7e81916897400f39bd56165e0585bc5e85b1f45db9b10bfefcc' 
  AND token = 'Zq/dVkLGmFFwzTnh8CUlHcaFfTHtVEqxG7Wl4liZ0RI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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